SPARQL refers to:
[[
[UNICODE]
The Unicode Standard, Version 4. ISBN 0-321-18578-1, as updated from
time to time by the publication of new versions. The latest version of
Unicode and additional information on versions of the standard and of
the Unicode Character Database is available at
http://www.unicode.org/unicode/standard/versions/.
]]
which cites a moving target. Please define SPARQL in terms of a
particular version of Unicode only, and no other. Otherwise if or when
this Unicode consortium makes some incompatible changes, all existing
implementations become invalid.
EricP said it was because of http://www.w3.org/TR/charmod/#sec-RefUnicode
which seems to go counter to stable implementations.
Maybe you can alter the wording so that implementing Unicode 4 alone is
sufficient and using any later versions is not required.
The charmod refernence mostly says this in that the latter is a MAY and
the former is needed "if it is desired that characters allocated after a
specification is published are usable with that specification". Which
may not be a desire.
Dave